1. Field of the Invention
The present invention relates to an input device capable of generating various input signals using a capacitive input pad in combination with a switch.
2. Description of the Related Art
U.S. Pat. No. 5,790,106 and corresponding Japanese Unexamined Patent Application Publication No. 8-137607) disclose a capacitive input pad having a plurality of X-electrodes and Y-electrodes arranged in a matrix.
In this input pad, the plurality of X-electrodes are arranged on one surface of a glass substrate, whereas the plurality of Y-electrodes are arranged on the other surface of the glass substrate. The X-electrodes and the Y-electrodes are arranged in a matrix through the glass substrate, and a predetermined capacitance is formed between each X-electrode and the corresponding Y-electrode.
After a control unit brings a state into a state that each of the X-electrodes is connectable to an oscillation circuit and turns each of the Y-electrodes on, a predetermined potential is applied to each of the X-electrodes and each of the Y-electrodes. When a conductor, such as a finger, touches the input pad in this state, an electrostatic field between each of the X-electrodes and the corresponding Y electrode changes. A voltage that has changed due to this change in the electrostatic field is output from each Y-electrode. The changed voltage output from each Y-electrode is supplied to the control unit through an A/D (Analog-to-Digital) converter or the like. A voltage detector that is provided in the control unit can detect a position pressed with a finger or the like by specifying a position at which the electrostatic field between the X-electrode and the Y-electrode changes on the basis of the data supplied from the A/D converter.
In an operation panel provided in personal computers or the like, an input pad is arranged on the proximal side with respect to a keyboard input unit. An operator operates input keys of the keyboard input unit using each finger with both of their palms resting on both sides of the input pad. Additionally, when the operator operates the input pad, the operator moves the palm of their dominant hand from the operation panel, and touches the input pad with a finger of the dominant hand. Through this operation, the operator moves a pointer displayed on a screen, selects each menu screen displayed on a screen, and performs a tapping operation.
However, the input operations performed using the input pad are limited to operations, such as movement of a pointer on a display screen and selection of a menu screen. Additionally, switching input operations through tapping are also limited to preset input modes. To perform input operations other than the preset ones using the input pad, it is necessary to activate driver software installed in a personal computer, to display a management screen, and to change settings. Accordingly, performing various input operations using the input pad is limited unless settings are changed on the management screen.